This invention relates to accounting for postal charges for batches of items of mail.
Postage meters for dispensing postage in respect of charges for mail items are known. In so-called pre-payment meters, a value of credit is stored in the postage meter and this value of credit is decremented by the amount of postage charge as each mail item is processed. Periodically, when the value of credit becomes low, payment for further postage is made and the credit value in the postage meter is reset. Other postage meters operate in a post payment mode in which the postage meter stores an accumulated aggregate value of postage dispensed in applying postage charges to mail items. Periodically the accumulated aggregate value of postage dispensed by the postage meter is determined by the postal authority and the user of the postage meter is billed for the value of postage dispensed.
When processing batches of mail which may contain relatively large numbers of mail items, it is convenient for accounting to be effected in respect of each batch of items and to make a payment in respect of each batch. Accordingly it has been proposed to create a statement of mailing in respect of the items in a batch. The statement of mailing contains data relating to the mail batch and this statement of mailing is used to effect a transfer of funds from the mailer's account to the account of the postal authority. Since the statement of mailing provides the basis for payment for postage charges it is necessary that the statement of mailing is created in a secure manner and that its authenticity can be verified. Accordingly the statement of mailing is digitally signed.